Criss Angel was rushed to a Vegas ER Friday after passing out during a straight jacket act.

Chris was performing for his Mindfreak Live! gig Friday night at the Luxor Hotel, where eyewitnesses say the show was canceled 10 minutes into the opening act ... after Criss dangled upside down in a straight jacket and attempted to escape.

After spinning in vain for about 2 minutes, he was quickly lowered down and the curtain closed onstage. We're told he appeared unconscious as guests were ushered out.

Criss was taken to Spring Valley Hospital Medical Center's emergency room about 4 miles away, and we're told he was discharged the same night. A source tells us he "walked out of here" sometime before 10 PM.

A rep for Criss says he did in fact lose consciousness Friday night during his straight jacket act and was taken to the hospital for evaluation, where he was released. He's undergoing additional testing Saturday to see if he can perform for tonight's show.